package com.example.demo;

import android.content.ContentValues;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.ListView;

import java.io.File;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity implements IOnDataChangeListener{
    private ListView lvStu;
    private Button btnAdd;
    private ArrayList<Student> studentArrayList = new ArrayList<>();
    private StuAdapter adapter;
    private EditText edtKey;
    private ImageView ivSearch;
    private StuSqLiteOpenHelper stuSqLiteOpenHelper;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        findViews();

        //创建student
        stuSqLiteOpenHelper =new StuSqLiteOpenHelper(MainActivity.this,
                "stu.db",null,1);
        SQLiteDatabase db = stuSqLiteOpenHelper.getWritableDatabase();
        db.close();

//        initStudentArrayList();

        adapter = new StuAdapter(MainActivity.this, studentArrayList,MainActivity.this);
        readDataFromDB();

        lvStu.setAdapter(adapter);
        lvStu.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Student student = studentArrayList.get(position);
                Intent intent = new Intent();
                intent.setClass(MainActivity.this,EditActivity.class);
                intent.putExtra("STUNO",student.getStuno());
                intent.putExtra("NAME",student.getName());
                intent.putExtra("AGE",student.getAge());
                startActivityForResult(intent,3001);
            }
        });
    }

    /**
     * 从数据库读取学生列表
     */
    private void readDataFromDB() {
        SQLiteDatabase db = stuSqLiteOpenHelper.getReadableDatabase();

        studentArrayList.clear();
        Cursor cursor = db.query("student", null,null,
                null,null,null,null,null);

        if(cursor == null || cursor.getCount()>0){
            for(cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()){
                String stuno = cursor.getString(0);
                String name = cursor.getString(1);
                int age = cursor.getInt(2);

                Student  student = new Student(stuno, name, age);
                studentArrayList.add(student);
            }
//            return;
        }
        adapter.notifyDataSetChanged();
        cursor.close();
        db.close();
    }

    private void initStudentArrayList() {
        studentArrayList.add(new Student("17001","lisa", 18));
        studentArrayList.add(new Student("17002","lier", 18));
        studentArrayList.add(new Student("17003","liwu", 18));
        studentArrayList.add(new Student("17004","liqi", 18));
    }

    private void findViews() {
        lvStu = findViewById(R.id.lv_stu);
        btnAdd = findViewById(R.id.btn_add);

        btnAdd.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent();
                intent.setClass(MainActivity.this, AddActivity.class);
                startActivityForResult(intent, 1001);
            }
        });

        edtKey=findViewById(R.id.edt_key);
        ivSearch = findViewById(R.id.iv_search);
        ivSearch.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String key = edtKey.getText().toString();
                searchFromDB(key);
            }
        });

        edtKey.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {

            }

            @Override
            public void afterTextChanged(Editable s) {
                String key = edtKey.getText().toString();
                searchFromDB(key);
            }
        });
    }

    private void searchFromDB(String key) {
        SQLiteDatabase db = stuSqLiteOpenHelper.getReadableDatabase();

        String where = "name like '%"+ key +"%' or stuno like'%"+
                key +"%' or age = '"+ key+"'";
        studentArrayList.clear();
        Cursor cursor = db.query("student", null,where,
                null,null,null,null,null);

        if(cursor == null || cursor.getCount()>0){
            for(cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()){
                String stuno = cursor.getString(0);
                String name = cursor.getString(1);
                int age = cursor.getInt(2);

                Student  student = new Student(stuno, name, age);
                studentArrayList.add(student);
            }
//            return;
        }
        adapter.notifyDataSetChanged();
        cursor.close();
        db.close();
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if(resultCode == 2001){
            String stuno = data.getStringExtra("STUNO");
            String name = data.getStringExtra("NAME");
            int age = data.getIntExtra("AGE", 0);

            Student student =  new Student(stuno, name, age);
            addStudentToDB(student);
        }else if (requestCode == 3001){
            String stuno = data.getStringExtra("STUNO");
            String name = data.getStringExtra("NAME");
            int age = data.getIntExtra("AGE", 0);

            Student student = new Student(stuno,name,age);
            updateStudentToDB(student);
        }

    }

    private void updateStudentToDB(Student student) {
        SQLiteDatabase db = stuSqLiteOpenHelper.getWritableDatabase();

        //组装语句
       /* String sql = "update student set name ='"+student.getName()+"'," +
                "age = "+student.getAge()+" where stuno ='"+student.getStuno()+"'";
        db.execSQL(sql);
        db.close();
        readDataFromDB();*/

        //update
        ContentValues values = new ContentValues();
        values.put("name",student.getName());
        values.put("age",student.getAge());
        String where = "stuno='"+student.getStuno()+"'";
        db.update("student",values,where,null);
        db.close();
        readDataFromDB();
    }

    private void addStudentToDB(Student student) {
        SQLiteDatabase db = stuSqLiteOpenHelper.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put("stuno", student.getStuno());
        values.put("name", student.getName());
        values.put("age", student.getAge());

        db.insert("student", null, values);
        db.close();
        readDataFromDB();
    }

    @Override
    public void del(Student student) {
        SQLiteDatabase db = stuSqLiteOpenHelper.getWritableDatabase();

        //用execSQL()
        /*
        String sql = "delete from student where stuno ='"+student.getStuno()+"'";
        db.execSQL(sql);
        db.close();
        readDataFromDB();
       */

        //用delete接口
        /*
        String where = "stuno = '"+student.getStuno()+"'";
        db.delete("student",where,null);
        db.close();
        readDataFromDB();
        */

        //用delete接口2
        String where = "stuno = ?";
        String[] argArray = {student.getStuno()};
        db.delete("student",where,argArray);
        db.close();
        readDataFromDB();
    }
}

